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Last modified by Xiaoling on 2024/08/16 11:25
From version 18.1
edited by Edwin Chen
on 2022/11/01 00:00
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To version 10.4
edited by Xiaoling
on 2022/10/15 16:26
Change comment: There is no comment for this version

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1 -XWiki.Edwin
1 +XWiki.Xiaoling
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10 10  In real-world deployment for LoRa, distance is a common topic. We always want to have the longest distance. This chapter shows some instructions for how to improve this.
11 11  
12 12  
13 -
14 14  = 2.  Analyze at the software side =
15 15  
15 +
16 16  == 2.1  LoRa parameters that effect distance ==
17 17  
18 18  
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44 44  |(% style="width:134px" %)**US915**|(% style="width:400px" %)20 or 22 dBm (depends on max output of module)|(% style="width:362px" %)SF=10|(% style="width:102px" %)125Khz
45 45  |(% style="width:134px" %)**AS923**|(% style="width:400px" %)14dBm|(% style="width:362px" %)SF=12|(% style="width:102px" %)125Khz
46 46  
47 +
48 +
47 47  == 2.2  Adaptive Data Rate (ADR) and set max distance ==
48 48  
49 49  
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72 72  According to the above technology, if we have a problem on the distance, we can first check if the end node is trying to longest distance modulation already. We can see that from the LoRaWAN server. Below is an example from Chirpstack.
73 73  
74 74  
75 -We can see the traffic in gateway's page and know that the distance is SF12 / BW125. (note, server is not able to know Transmit Power settings from End Node)
77 +We can see the traffic in gateway’s page and know that the distance is SF12 / BW125. (note, server is not able to know Transmit Power settings from End Node)
76 76  
77 77  
78 78  [[image:image-20221006185826-3.png]]
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84 84  
85 85  Below are the settings for longest distance transmission. ( will reduce battery life)
86 86  
87 -* (% style="color:#037691" %)**AT+ADR=0**     (%%)~/~/  Disable ADR
88 -* (% style="color:#037691" %)**AT+DR=  0**     (%%)~/~/  Use the smallest DR
89 -* (% style="color:#037691" %)**AT+TXP=0**    (%%) ~/~/  Use max power.
89 +* (% style="color:#037691" %)AT+ADR=0     (%%)~/~/  Disable ADR
90 +* (% style="color:#037691" %)AT+DR=  0     (%%)~/~/  Use the smallest DR
91 +* (% style="color:#037691" %)AT+TXP=0    (%%) ~/~/  Use max power.
90 90  
91 91  
92 -= 3.  Analyze at the hardware side =
93 93  
94 -== 3.1  Check if the antenna path is good ~-~- For LSn50v2 series end node ==
95 += 3.  Installation Guidelines =
95 95  
96 96  
97 -a) Open Enclosure and Check if the antenna connection to module is good.
98 +== 3.1  Check the use environment ==
98 98  
99 -b) check if the connector match.
100 100  
101 -
102 -[[image:image-20221016081725-1.png||height="426" width="706"]]
103 -
104 -
105 -
106 -= 4.  Installation Guidelines =
107 -
108 -== 4.1  Check the use environment ==
109 -
110 -
111 111  First , User should notice: Radio link quality and performances are highly dependent of the environment.
112 112  
113 113  (% style="color:blue" %)**Better performances can be reached with:**
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117 117  * No high level radio interferes in the ISM band you use.
118 118  * At least 1 meter above the ground.
119 119  
110 +
111 +
120 120  (% style="color:blue" %)**Radio performances are degraded with:**
121 121  
122 122  * Obstacles: buildings, trees...
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125 125  * Radio communication are usually killed with bad topographic conditions. It is usually not possible to communicate through a hill, even very small.
126 126  
127 127  
128 -== 4.2  Improve the Antenna ==
129 129  
121 +== 3.2  Improve the Antenna ==
130 130  
123 +
131 131  In some case, we have to install the device inside the chamber or next to a metal case. So the signal between the antenna and the receiver (gateway) is blocked by the metal. This will greatly reduce the signal. In such case, we can consider using antenna extend cable to extend the antenna to a better position.
132 132  
133 133  
134 134  
135 -= 5.  Some real-world case =
128 += 4.  Some real-world case =
136 136  
137 -== 5.1  Server reason cause end node has problem on Join. ==
138 138  
131 +== 4.1  Server reason cause end node has problem on Join. ==
139 139  
133 +
140 140  In one case, the customer is using AWS IoT Core and gateway to connect to AWS via Basic Station Connection, Frequency Band is AU915 sub-band 2. For some unknown reason, AWS always set downlink power to 0dBm, which cause the gateway only emit a very low power and lead to a short distance for sensor.
141 141  
142 142  
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150 150  
151 151  Reference Link:  [[http:~~/~~/wiki.dragino.com/xwiki/bin/view/Main/Change%20Gateway%20Power/#H1.A0Overview>>http://wiki.dragino.com/xwiki/bin/view/Main/Change%20Gateway%20Power/#H1.A0Overview]]
152 152  
153 -
154 -== 5.2 Chirpstack Default settings to 64 channels which cause Signal Poor. ==
155 -
156 -
157 -In this case, User use a Chirpstack LoRaWAN server with default settings. The Frequency Band is US915 and default settings of Chirpstack has all channels ( All sub-bands , total 72 channels) enable. User use a LDS03A and a LPS8N LoRaWAN gateway for the test.
158 -
159 -
160 -There is a strange issue: LDS03 has a very good RSSI ( RSSI=-40) during OTAA Join. But The LDS03A give a very poor RSSI after OTAA Join. After debug, it proves that the issue is with ChirpStack Frequency band settings. The ChirpStack server enables all 72 channels and the LDS03A will also use all channels after OTAA Join, but the LPS8N only can support 8 channels and set to Sub-Band2. When the LDS03A sends an uplink packet in the channel LPS8N doesn't support, because LDS03A is very close to LPS8N, LPS8N pick up this not support frequency and send to server. So in the platform we see a uplink packet with very poor RSSI.
161 -
162 -
163 -Above issue was confirmed and solved after set the ChirpStack support channels to sub-band2. See below for photos during debug.
164 -
165 -[[image:image-20221031233628-2.png]]
166 -
167 -
168 -[[image:image-20221031233759-3.png]]
169 -
170 -
171 -[[image:image-20221101000006-1.png||height="353" width="931"]]
172 -
173 -
174 -
175 -
176 -
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